Adverse events during treatment of nontuberculous mycobacterial lung disease: do they really matter?

Abstract : Treatment of nontuberculous mycobacterial lung disease (NTM LD) is long and hampered with frequent adverse events. Side effects may explain the poor prognosis associated with this disease. Our hypothesis was that adverse events might be responsible of premature discontinuation of treatment, thus leading to an increased mortality. We conducted a retrospective study including adult patients treated for NTM LD at 5 French hospitals between January 1st 2010 and December 31st 2015. Patients with cystic fibrosis were excluded. 71 patients were included, of which 45 had a pulmonary disease due to Mycobacterium avium complex and 15 due to M. xenopi. All patients fulfilled the ATS clinical and microbiological criteria for NTM LD. While treated, 72% of patients presented at least one reported side effect, of which 65% were gastro-intestinal and 21% were ophthalmologic. 14 patients stopped prematurely their treatment while initial therapy was modified in 22 cases due to poor tolerance. Adverse events were more common in patients who had been previously treated for NTM LD (p=0.02). Early treatment cessation was associated with the absence of sputum conversion (p=0.014) but not with mortality (p=0.237). Occurrence of adverse events was not associated with mortality. 15 patients died, among them 6 were under treatment. Mortality was associated with use of systemic steroids and existence of comorbidities, especially pulmonary or cardiovascular ones, as well as extra pulmonary cancers. Side effects of drugs used to treat NTM LD are common and responsible for early cessation of treatment that may result in a lack of sputum conversion. However, they did not affect mortality in our cohort.